Studies on different forms of potassium in soils of subtropical zone of Jammu region

Water soluble, exchangeable, 1N-HNO₃-soluble, HCl soluble and total K were determined in soils of Subtropical irrigated and unirrigated zones, representing two depths viz., 0–22.5 cm and 22.5–45.0 cm. There was large variation in the content of all forms of K depending upon soil texture, mineralogy of sand and clay fractions as well as soil properties. In soils of both the groups, the water soluble K and the exchangeable K were more in soils having 0–22.5 cm depth than those having 22.5–45.0 cm. Based on average values most of the Subtropical irrigated soils were medium to high in available K content (water soluble K + exchangeable K), while those of unirrigated (Kandi belt of Jammu) were medium in this respect. The amount of 1N-HNO₃ soluble K generally increased with depth in soils of both the groups. Total K content was high (> 1%) in all the soils under the present study. Like other forms of K, a large variation was also observed in HCl soluble K.